Saw this on TV tonight. Fair Oak Farms is a huge working dairy about 75 miles from Chicago in NW Indiana. They give tours of their massive operation, including viewing cows being milked and baby cows being born (about 80! a day). They also have an interactive play area and other kid activities, as well as cheese and ice cream on sale in their cafe. Looks like it's $7/adult, $4 for kids 3-11. Might be worth a weekend drive out to explore, especially if you're a cow and dairy fanatic like my daughter is.